The Molecular Virology Basic Research Program (MVBRP) is an interdisciplinary basic research Program consisting of 17 independent but interactive laboratories with common interests in the molecular biology and immunology of viruses relevant to cancer and related topics. The overall goal of this Program is to facilitate research into the basic mechanisms of viral tumorigenesis and viral immunology;to conduct investigations that may lead to novel approaches to prevent or treat tumors associated with viruses;or to use viruses themselves as vaccines or oncolytic agents. Under the leadership of Daniel DiMaio, M.D., Ph.D., a tumor virologist who focuses on papillomaviruses, the MVBRP accomplishes these goals primarily by sponsoring the Molecular Virology and Oncology Group Meetings and the Steven Degar Memorial Lectureship, by encouraging and stimulating collaborative research, and by providing access to YCC funds and shared resources. Dr. DiMaio, along with other Program faculty, directs the graduate level course, The Molecular Biology of Animal Viruses. He is also the Principal Investigator of the NCI-funded Program Project Grant, Molecular Basis of Viral and Cellular Transformation, as well as an NCI-funded postdoctoral training grant in tumor virology and an NIAID-funded predoctoral training grant in virology. The distinguished faculty of this Program includes members of the National Academy of Sciences (Steitz) and the Institute of Medicine (Miller and Steitz). In aggregate, the Program members have received seven NIH MERIT Awards. There are now substantial efforts in the areas of basic tumor virology, vaccine development and viral immunology, and oncolytic viruses. In the last grant period, members of this Program published 243 cancer related papers, of which 4.1% were intra-programmatic and 18% inter-programmatic. Because viruses play a causal role in a substantial fraction of human tumors, studies carried out in this Program may eventually have an important impact on cancer prevention and treatment by revealing the mechanisms responsible for viral replication and tumorigenesis, thus identifying novel targets for translational efforts. In addition, these studies will reveal the mechanistic basis of biological phenomena that are relevant to the development and treatment of many cancers, including those not associated with viruses. The Molecular Virology Program currently has 18 members from 12 departments, with total research funding of $7.2 million direct costs ($10.6 million total costs), of which $6.3 million direct costs is peer-reviewed and $2.7 million direct costs is NCI-funded.